Gerald Koch said:Yes. It is the carbonyl (-CO-) group in both acetone and formaldehyde which reacts.
Photo Engineer said:While I agree with this statement, I question the rate at which it proceeds and the yield that it gives.
If either rate or yield is off, you don't get the amount of base that you are entitled to.
My question is this... Was part "B" cloudy? This is a characteristic of the reaction when the paraformaldehyde reaction does not take place or is slow or is incomplete. In that case, there was not enough base formed. If acetone was used, remaining acetone odor is the clue that things didn't work as expected.
This is a neat way to get base, but I wouldn't do it myself for any reason other than avoiding handling sodium hydroxide. But then you are substituting formalin. Nice tradeoff.
PE
nextreme said:Hi, yes part B is cloudy, and still has a strong acetone odor. Working solution is clearer, maybe just a tint of cloudiness, and has a much less pronouced acetone odor.
Can I fix this, or is it just no good ? Also, was considering trying Ansco 81, but I can't find dilutions to use with paper developing.
Many thanks for all the replies !
Steven
psvensson said:Looking at the formula, I would guess that acetone is in excess in B, so that it can absorb the sulfite in A when the solutions are mixed together. So it would make sense that even as designed, part B would have an acetone smell.
nextreme said:Hello Everyone, I just tried mixing ...
D-85 Two Solution Lith Developer
Solution A
Water at 125° F 500 ml
Sodium sulphite 36.5 g
Boric acid crystals 9.4 g
Hydroquinone 28 g
Potassium bromide 2 g
Water to make 1 litre
Solution B
Water at 90 ° F 500 ml
Sodium bisulphite 11 g
Sodium sulphite 1 g
Paraformaldehyde 37.5 g
Water to make 1 litre
QUOTE]
By way of contrast, Wall's Normal Hydroquinone:
Solution A;
Sodium Sulfite 100 grams
Hydroquinone 20 grams
H2O to make 1 liter
Solution B;
Sodium Carbonate 110 grams
H2O to make 1 liter
I've substituted 110 grams of S. CO3 for the 120
grams of P. CO3 in the original formula.
Mix 1:1 and dilute for paper ???
That they don't say. Well, lith is for film is it not?
Those three chemicals will produce lith prints. I concocted
a Wall's similar developer which worked well. If you give Wall's
Normal Hydroquinone a try use it one-shot. I would brew up
a 1/20 batch and test. Only enough sulfite should be used
to preserve the hydroquinone. I think the HQ to CO3
ratio in the ballpark. You may wish to tweak. Dan
nextreme said:Not sure how I will proceed yet, but I'll
probably try another formula.
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